doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Barrel Burst- Beretta 682?

Just to clarify, the shell in the top barrel did fire when the lower barrel burst?

I believe the double ring bulge, which clearly establishes the presence of an obstruction, was 1. an object (base wad, tipped shot wad, or all/part of the hull) in the lower barrel causing a bulge prior to rupture and 2. the lower barrel bulge obstructed the bore of the top barrel.

Had the lower shell head separated from the hull?



Burrard's "Wave Theory" may also apply

Major Sir Gerald Burrard in the second edition of The Modern Shotgun (1948), Volume 3, The Gun and The Cartridge, �The Diagnosis of a Burst� discussed �Wave� Pressures and the etiology of multiple bulges pp. 364-375.
p. 365
When the explosive charge was placed entirely at one end of the closed vessel (discussing experiments by Paul Marie Eug�ne Vieille and published in Etude des Pressions Ondulatoires in 1890) the gases given off naturally rushed forwards along the length of the vessel until the forward layer of gases was suddenly checked by the closed end. When this occurred the gases which were behind the extreme forward layer over-took this layer and began to pile up against it, with the result that the extreme forward layer was compressed with great violence. It was this compression of the extreme forward layer of gases which caused the high pressure�
p. 368
Since this wave pressure acts radially outwards the wall of the barrel is submitted to a very severe pressure all round its circumference, and if the pressure is sufficient to stress the barrel beyond the elastic limit of the steel a permanent bulge all round the bore is the result. Such a bulge is knows as a �Ring Bulge� �
p. 374
If the wave pressure was not sufficient to burst the barrel...the shot charge and obstruction will continue to travel along the bore under the influence of the expanding powder gases, but the wave pressure will be reflected backwards and will occur again at the extreme end of the cartridge-case. It will then rush forward once more (third wave) and may overtake the shot charge�in which case it will act again immediately behind the wads.
It is possible for the third wave pressure to be sufficiently violent to bulge the barrel some way ahead of the site of the first wave pressure, in which case one obstruction would be responsible for two ring bulges.

Good information, Drew, but as mentioned the gun came apart so violently that the two halves separated of their own accord; and looking for case head separations, missing base wads, etc. became a distant second to stanching the bleeding and getting him to the ER some distance away. No one involved can say whether the top barrel shell actually discharged simultaneously, or not, but I could believe the bottom barrel incident possibly jarring the sear out of the notch (or bent) to where it sounded like one discharge to those present. Though they do not show in the photos, the gapes from the mono-block for both barrels are approx. 1/32" in width occurring for about 1/4 of the barrel circumferences. Seems that without the evidence of those hulls involved nothing can be really said definitively, but my friend is just trying to understand the possible 'why' of it happening......which is why I brought it to you guys.

The incident occurred last weekend at Big Sky Sporting Clays out of Polson, MT, a high volume operation where some of you have probably shot at one time or another. I mention this because spent hulls abound there in the tens of thousands and no way to confirm which ones were involved in his accident..... even if any damaged ones were to be found.

Nonetheless, your info from Maj. Burrard is appreciated....all good stuff.

Rob

I had friends that had events with 682's. An old DR friend double charged some 1 1/8 reloads and when he shot one the first one pushed him down to the ground! , NO damage to the gun. Another fellow blew up a tube at the muzzel. He returned the gun and the factory cut off the tubes behind the damage, crushed the barrels in a vise and sent it back. I would talk to both vendors but watch out on loosing control of evidence.
Is it a reflection causing the gold colored band or a seam in the tubing stock?
bill

I think the top barrel bulge is more of a curiosity than the bottom barrel burst. At the start of the thread, Rob noted the the top barrel bulge 'is very uniform circumferentially'. The other thing is that the upper barrel bulge seems to be a visible bit downstream of the lower barrel bulge, though the burst extends further. It may seem that if an obstruction caused the upper bulge, it was past the point that the lower barrel bulged before failing.

I wonder if bulges on both barrels may have been present or forming without being noticed. It just seems odd to have two bulges in a similar location on different barrels. If it wasn't the loads, were the barrels weaker for some reason or another in about the same place, forcing cone or back boring work? Just thoughts. Your explanations Doc Drew are always well thought through and supported.

Rob, thanks for sharing the incident, and I'm glad your buddy is doing okay.

I seem to remember Bruce Bowen trying to blow up a single barrel (inexpensive) gun without much success. The information was posted on Trapshooters.com but I have been unable to access the correct thread. Drew do you remember his postings and the thread?

jlb

It's a very rare event on 680 series guns.
If you remove the stock you'll know if it was a double discharge.

I always worry if older gun barrels have been tinkered with. Listening to all the mythology at my club makes me uncertain of their sanity.

When I've been involved with a similar situation, the cartridge maker couldn't help fast enough. In return for the barrels.

Please tell how by removing the stock you can tell if the gun double discharged?

I doubt that you will ever find the reason for the burst and you could theorise all day .Personally I would plum for blockage . But as has been said before you hardly ever notice a bulge when shooting so damage could have occurred prior to the burst .It is odd that I have seen several Bertta's with bulges/burst barrels and it has always been the bottom .

For clarification, I should recap that the shooter was set-up to fire the lower barrel first, then upper....

That the last photo that appears here is taken from the right-side view of the gun..........

And lastly, the involved party is just delighted to still have his vision intact along with his thumb and four fingers....i.e. not the litigious sort.

'Thanks' to all,

Rob

"The gun involved is a 12 ga. Beretta 682 and its owner was shooting factory Federal promo loads (Top Gun- multi-purpose shell 1-1/8 oz. - 1200 fps) like you�d buy a four-pak of in Wal-Mart. He was three stations into a round of sporting clays with no issues when they let go, injuring his left hand as pictured. At the explosion, the forearm fell off in three or four pieces,and the barrels fell away from the frame without his initiating that. He was injured enough to where he and his friends were thinking more about hospitals rather than where the empty cartridges went, so we don�t have that to work from�"

Unless he recocked it, the tumbler will either be engaged or not.
In the moments following the injury, I doubt it was reassembled, and recocked.

At least that's my take on it.

Stan,

Thank your the explanation. After all these years of reloading I am only familiar with compression formed hulls.